NEW York City Ballet found itself with a major repertory piece on its hands after Tuesday’s spring gala at the New York State Theater.

It’s called “Evenfall,” and – set to Bartok’s Third Piano Concerto and choreographed by the troupe’s resident choreographer, 33-year-old Christopher Wheeldon – it’s as close to a work of genius as one can call at a first viewing.

The whole idea behind New York City Ballet’s Diamond Project, which will have offered six world premieres by the end of the season, is choreographic novelty.

It brings something fresh and interesting for the audience to watch, something challenging and different for the dancers to perform, something rewarding in experience for the choreographers to create.

Most of the creations will have a few performances this season and perhaps next, and then be put aside. Once in a very rare while, an “Evenfall” breaks the mold.

Before this Wheeldon, we had a new Peter Martins piece, “The Red Violin,” to John Corigliano’s wet and windy violin concerto of the same name, based on film music.

With the solo part beautifully played by joint concertmaster Kurt Nikkanen, the music offered a sagging framework for choreography that found Martins at his least inspired. The six dancers did their valiant best, but only Jennie Somogyi offered anything like individuality.

On the happier hand, Wheeldon’s “Evenfall” proved a surely unintended but triumphant homage to Balanchine’s “Ballet Imperial.” In its shape and architectonics – it uses two principals, Miranda Weese and Damian Woetzel, plus an ensemble of 12 women and six men – it matches, with renewal rather than imitation, Balanchine’s invention in detail and design.

Just as Balanchine in the earlier ballet caught the imperial chandelier spirit of Tchaikovsky and his own choreographic master, Marius Petipa, so Wheeldon has seen Bartok as the last of the great musical romantics, and Balanchine as the key to his exploration.

The results spread across the stage like a banquet of dance – a feast to be remembered, a ballet to be nurtured.

—

EVENFALL

New York City Ballet, New York State Theater, 20 Lincoln Center; (212) 870-5570. Season runs through June 25.